The other day I was lucky enough to witness an honest-to-goodness mini-hurricane whilst driving back to the office. Since it was on a dusty plain, the loose soil getting sucked in made the shape really well-defined, and it was big enough that I could've fit the SUV I was in completely inside.
For a moment I considered doing so, to see if such a big foreign object would disrupt it, but I figured that with my luck, some expensive exterior part would get torn off & flung out to parts unknown, and I'm a cheapskate like that.